Retractable water jet for a water jet/steering and propulsion system

ABSTRACT

A vertically moveable water jet thruster unit for a water jet propulsion and steering system of a water vessel. The water jet unit comprises a stationary support cylinder rigidly affixed to the hull of the water vessel, a rotatable support cylinder mounted in the stationary cylinder on roller bearings, and a vertically moveable water jet disposed in the rotatable support cylinder in guide tracks. Vertically disposed guide members affixed to the water jet are disposed in the tracks in the rotatable cylinder and guide the water jet vertically upwardly into the water vessel when an underwater collision occurs.

United States Patent Stelling [451 Dec. 25, 1973 Primary ExaminerTrygveM. Blix Assistant ExaminerStuart M. Goldstein Att0rneyAllison C. Collard5 7 ABSTRACT A vertically moveable water jet thruster unit for a waterjet propulsion and steering system of a water vessel. The water jet unitcomprises a stationary support cylinder rigidly affixed to the hull ofthe water vessel, a rotatable support cylinder mounted in the stationarycylinder on roller bearings, and a vertically moveable water jetdisposed in the rotatable support cylinder in guide tracks. Verticallydisposed guide members affixed to the water jet are disposed in thetracks in the rotatable cylinder and guide the water jet verticallyupwardly into the water vessel when an underwater collision occurs.

RETRACTABLE .WATER JET FOR A WATER JET/STEERING AND PROPULSION SYSTEMThe present invention relates to water jet propulsion and steeringsystems for water vessels, and in particular to a vertically movablewater jet for use with a water jet propulsion and steering system whichretracts into the hull of the water vessel when it strikes an underwaterobject.

It is known that severe damage can be done to the hull of a water vesselwhen underwater objects are struck. This is particularly so in shipsequipped with water jet propulsion systems, since the water jets arerigidly and integrally constructed with the hull of the ship, and veryextensive damage may be done to the water vessel if a water jet unit isripped from the hull by the impact of an underwater collision.

Accordingly, the present invention provides a water jet thruster unitwhich is constructed so as to prevent damage to itself and the hull ofthe water vessel in which it is disposed. The water jet unit of thepresent invention comprises a stationary cylindrical support memberrigidly affixed to the hull of the ship in which a rotatable cylindricalsupport member is disposed. The rotatable member is mounted on ballbearings disposed in grooves provided in both support members, and ismoveable through an angle of 360. The rotatable support member is alsocoupled to the steering mechanism of the water vessel, which changes thedirection of the water jet with respect to the hull of the ship andthereby steers the water vessel. The water jet is slidably disposed inthe rotatable support member, and includes a pair ofvertically-disposed, U-shaped projecting members, in which ball bearingsare disposed, which are slidably disposed in guide tracks provided inthe rotatable support member. When an underwater object strikes thewater jet, the force of the collision pushes the jet upwardly in theguide tracks into the hull of the water vessel so that it slides overthe object. As soon as the obstruction is passed by the ship, thewaterjet slides downwardly out of the hull to resume its normaloperation.

It is therefore an object of the present invention to provide a waterjet thruster unit for the water jet propulsion and steering system of awater vessel which is automatically retractable into the hull of thewater vessel when struck by an underwater object.

It is another object of the present invention to provide a water jetthruster unit for the water jet propulsion and 360 steering system of awater vessel which will not damage the hull of the water vessel duringan underwater collision.

It is a further object of the present invention to provide a water jetthruster unit for a water vessel waterjet 360 steering and propulsionsystem which is simple in design, easy to manufacture and efficient andreliable in operation.

Other objects and features of the present invention will become apparentfrom the following detailed description taken in connection with theaccompanying drawings which disclose an embodiment of the invention. Itis to be understood, however, that the drawings are designed for thepurposes of illustration only, and are not intended as a definition ofthe limits and scope of the invention.

In the drawings, wherein similar reference numerals denote similarelements throughout the several views:

FIG. 1 is a cross-sectional side view of a water jet thruster unitconstructed in accordance with the present invention; and

FIG. 2 is a cross-sectional top view of the water jet thruster unit,taken along section 2-2 of FIG. 1.

Referring to the drawings, there is shown a water jet thruster unitcomprising a stationary support cylinder 10 which is secured to the hullll of a water vessel by bolts 12. A rotatable support cylinder 13 ismoveably disposed within stationary cylinder 10, and is mounted on upperand lower rings of roller bearings 14, which are disposed incircumferential grooves provided in the outside surface of cylinder 13and the inside surface of cylinder 10, so that cylinder 13 is rotatablethrough an angle of 360. Cylinder 13 is provided with a centralcylindrically-shaped water passageway 15 through which water underpressure is pumped to a water jet 16. The water jet is provided with acentrally disposed water passage 17, which channels the water frompassageway 15 to one or more, water jet nozzles 18 which I eject thewater substantially horizontally below the hull of the ship. Cylinder 13is provided with a pair of vertically disposed elongated tracks 19 inwhich a pair of vertically disposed, U-shaped projecting members 20provided on the water jet are disposed so as to guide the jet thrusterunit upwardly and downwardly therein and in cylinder 13 and secure thewater jet with respect to cylinder 13. Ball bearings 21 are disposed inprojecting members 20 in order to insure that the water jet moves easilyin cylinder 13. An annular plate 22 is secure to the bottom of hull 11below cylinder 13 and 10 to secure the cylinders, and includes anaperture 23 through which the bottom of the water jet is disposed.

Upon colliding with an underwater object, the curved side of water jet16 causes an upward force to be exerted on the waterjet which pushes itupwardly in guide tracks 19. The water jet moves into the hull of thewater vessel a distance corresponding to the height of the underwaterobject struck. The maximum distance the jet thruster unit will move intothe hull is the distance it extends from the bottom of the hull. Fullretraction of the water jet will occur when the water vessel is groundedor beached. A water shut-off safety valve (not shown), coupled to thewater jet propulsion system water pump, is provided to immediately shutoff the water pressure to the water jets of the system when they areretracted into the hull of the vessel in order to prevent damage to thesystem and to the water vessel. The described water jet thruster unitmay be in all types of water vessels, such as submarines, surface ships,and small motor boat craft. It is particularly suited for use in a 360water jet steering and propulsion system such as that disclosed inapplicants co-pending patent application, Ser. No. 244,079, filed Apr.14, 1972, entitled Water Jet Propulsion and Steering System for a Multi-Section Prime-Mover Ship. The materials used to construct the water jetthruster unit may be any suitable conventional materials used in theconstruction of marine vehicles.

While only one embodiment of the invention has been shown and described,it will be obvious to those persons of skill in the art that manychanges and modifications may be made thereunto without departing fromthe spirit and scope of the invention.

What is claimed is:

1. An automatically retractable water jet for the water jet steering andpropulsion system of a water vessel, comprising:

a first, stationary, cylindrical support member affixed to the hull ofthe water vessel;

a second movable cylindrical support member, rotatably disposed in saidfirst support member, and having a plurality of vertically-disposedguide tracks provided on the inside surface thereof; and

a water jet, having a plurality of vertically-disposed, radiallyoutwardly extending projecting members slidably disposed in said guidetracks, said water jet being slidable vertically upwardly in said secondcylindrical member, and being guided by said projecting members in saidguide tracks, when a vertically upwardly directed force is exerted onsaid water jet as a result of an underwater collision.

2. The water jet as recited in claim 1, wherein said projecting membersare U-shaped, and include a plurality of roller bearings disposed insaid projecting members for slidably guiding said projecting members insaid guide tracks.

3. The water jet as recited in claim 2, further comprising a pluralityof roller bearings, disposed between said first and second cylindricalsupport members, for rotatably mounting said second cylindrical supportmember in said first cylindrical support member.

4. The water jet as recited in claim 3, wherein a plurality of circularperipheral grooves are provided in the inside surface of said firstcylindrical support member and in the outside surface of said secondcylindrical support member, and wherein said roller bearings comprise aplurality of roller bearings disposed in an annular arrangement in saidgrooves provided in said first and second cylindrical support members,for rotatably mounting said second cylindrical support member in saidfirst cylindrical support member.

5. The water jet as recited in claim 4, wherein said plurality of rollerbearings in said projecting members are disposed in a vertical lineararrangement.

6. The water jet as recited in claim 5, wherein said water jet isprovided with a curved bottom surface extending from the hull of thewater vessel, and includes a plurality of water jet nozzles, fordirecting water under pressure from said water jet substantiallyhorizontally under the hull of the water vessel.

1. An automatically retractable water jet for the water jet steering andpropulsion system of a water vessel, comprising: a first, stationary,cyliNdrical support member affixed to the hull of the water vessel; asecond movable cylindrical support member, rotatably disposed in saidfirst support member, and having a plurality of vertically-disposedguide tracks provided on the inside surface thereof; and a water jet,having a plurality of vertically-disposed, radially outwardly extendingprojecting members slidably disposed in said guide tracks, said waterjet being slidable vertically upwardly in said second cylindricalmember, and being guided by said projecting members in said guidetracks, when a vertically upwardly directed force is exerted on saidwater jet as a result of an underwater collision.
 2. The water jet asrecited in claim 1, wherein said projecting members are U-shaped, andinclude a plurality of roller bearings disposed in said projectingmembers for slidably guiding said projecting members in said guidetracks.
 3. The water jet as recited in claim 2, further comprising aplurality of roller bearings, disposed between said first and secondcylindrical support members, for rotatably mounting said secondcylindrical support member in said first cylindrical support member. 4.The water jet as recited in claim 3, wherein a plurality of circularperipheral grooves are provided in the inside surface of said firstcylindrical support member and in the outside surface of said secondcylindrical support member, and wherein said roller bearings comprise aplurality of roller bearings disposed in an annular arrangement in saidgrooves provided in said first and second cylindrical support members,for rotatably mounting said second cylindrical support member in saidfirst cylindrical support member.
 5. The water jet as recited in claim4, wherein said plurality of roller bearings in said projecting membersare disposed in a vertical linear arrangement.
 6. The water jet asrecited in claim 5, wherein said water jet is provided with a curvedbottom surface extending from the hull of the water vessel, and includesa plurality of water jet nozzles, for directing water under pressurefrom said water jet substantially horizontally under the hull of thewater vessel.